Typst brand settings always triggered for creating title

[christopherkenny]

I have:

• searched the issue tracker for similar issues
• installed the latest version of Quarto CLI
• formatted my issue following the Bug Reports guide

Bug description

The current setup for Typst has incorrect logic for checking for brand metadata when creating the title heading block.

Specifically, the template currently sets the brand family to Libertinus Serif by default. This means that when checking if any of the brand components are set, it will always run this if for the header.

Steps to reproduce

Simply set mainfont without using a brand.yml file.

---
title: "Header logic"
format: typst
mainfont: Comic Sans MS
---

Some text.

# Header logic so we have the same letters

More text.

Everything should be in the whimsical comic sans font.

Actual behavior

Expected behavior

Everything should be in Comic Sans (for better or for worse).

Your environment

• IDE: RStudio 2025.09.0 Build 387
• OS: Windows 11

Quarto check output

Quarto 1.8.24
[>] Checking environment information...
      Quarto cache location: C:\Users\chris\AppData\Local\quarto
[>] Checking versions of quarto binary dependencies...
      Pandoc version 3.6.3: OK
      Dart Sass version 1.87.0: OK
      Deno version 2.3.1: OK
      Typst version 0.13.0: OK
[>] Checking versions of quarto dependencies......OK
[>] Checking Quarto installation......OK
      Version: 1.8.24
      Path: C:\Users\chris\AppData\Local\Programs\Quarto\bin
      CodePage: 1252

[>] Checking tools....................OK
      TinyTeX: (external install)
      Chromium: (not installed)

[>] Checking LaTeX....................OK
      Using: TinyTex
      Path: C:\Users\chris\AppData\Roaming\TinyTeX\bin\windows\
      Version: 2025

[>] Checking Chrome Headless....................OK
      Using: Chrome found on system
      Path: C:\Program Files\Google\Chrome\Application\chrome.exe
      Source: Windows Registry

[>] Checking basic markdown render....OK

[>] Checking Python 3 installation....OK
      Version: 3.13.7
      Path: C:/Python313/python.exe
      Jupyter: (None)

      Jupyter is not available in this Python installation.
      Install with py -m pip install jupyter

[>] Checking R installation...........OK
      Version: 4.5.1
      Path: C:/PROGRA~1/R/R-45~1.1
      LibPaths:
        - C:/Users/chris/AppData/Local/R/win-library/4.5
        - C:/Program Files/R/R-4.5.1/library
      knitr: 1.50
      rmarkdown: 2.29

[>] Checking Knitr engine render......OK

[gordonwoodhull]

This is a failure to test the prior mainfont when implementing brand.yml, i.e. a regression in v1.6.

The equivalent using brand.yml works:

---
title: "Header logic"
format: typst
brand:
  typography:
    base:
      family: Comic Sans MS
---

Some text.

# Header logic so we have the same letters

More text.

Fix incoming.

[christopherkenny]

Thanks @gordonwoodhull!